For machining printed circuit boards, there is an increasing demand for highly flexible, high-precision, high-output machines. For which purpose, drilling machines have been devised comprising a number of machining heads for simultaneously drilling a corresponding number of identical boards. Nevertheless, despite the high output achieved, the degree of flexibility of such machines is invariably poor.
A drilling machine is also known comprising a table movable along the usual Y axis and which may be loaded with a number of boards, even of different sizes; and a number of machining heads movable independently of one another along the usual X axis so as to machine boards of different sizes and/or different hole patterns.
The above machine has several drawbacks. In particular, setting the Y-axis position of the heads on the respective carriages is extremely complicated. Moreover, since the holes in the circuits are normally arranged in a matrix of rows and columns, the various heads can only operate simultaneously at locations along the same rows of the respective circuit boards, i.e. at locations having the same Y-axis coordinate. If any of the boards do not require drilling along a given row, the respective heads must remain idle until all the holes in that particular row have been drilled by the other heads, thus limiting the output of the machine as a whole.